NSX-T Uplink Profiles

Hi,

Can anyone explain why they specify VLAN 1647 and 1648 as Transport VLANs on the Uplink Profiles?

Ref. Create Uplink Profiles

They have already specified VLAN 1649 as the Transport VLAN.

Ref. Create Overlay Profile

So why are they using three VLANs for Edge Overlay traffic?

Thanks.